<!-- original admin tab content (commented out) -->
<div class="row justify-content-center">
    <div class="col-md-6">
        <div class="card shadow-sm">
            <div class="card-header bg-info text-white">
                <h2 class="h5 mb-0">
                    <i class="fa fa-cog mr-2"></i>系统管理
                </h2>
            </div>
            <div class="card-body">
                <div class="text-center py-5">
                    <i class="fa fa-lock fa-5x text-muted mb-4"></i>
                    <h3>管理员功能</h3>
                    <p class="text-muted mt-2">该功能需要管理员权限才能访问</p>
                </div>
            </div>
        </div>
    </div>
</div>
<!-- end original admin tab content -->